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001: #ifndef _LINUX_VHOST_H
002: #define _LINUX_VHOST_H
003: /* Userspace interface for in-kernel virtio accelerators. */
004: 
005: /* vhost is used to reduce the number of system calls involved in virtio.
006:  *
007:  * Existing virtio net code is used in the guest without modification.
008:  *
009:  * This header includes interface used by userspace hypervisor for
010:  * device configuration.
011:  */
012: 
013: #include <linux/types.h>
014: 
015: #include <linux/ioctl.h>
016: #include <linux/virtio_config.h>
017: #include <linux/virtio_ring.h>
018: 
019: struct vhost_vring_state {
020:         unsigned int index;
021:         unsigned int num;
022: };
023: 
024: struct vhost_vring_file {
025:         unsigned int index;
026:         int fd; /* Pass -1 to unbind from file. */
027: 
028: };
029: 
030: struct vhost_vring_addr {
031:         unsigned int index;
032:         /* Option flags. */
033:         unsigned int flags;
034:         /* Flag values: */
035:         /* Whether log address is valid. If set enables logging. */
036: #define VHOST_VRING_F_LOG 0
037: 
038:         /* Start of array of descriptors (virtually contiguous) */
039:         __u64 desc_user_addr;
040:         /* Used structure address. Must be 32 bit aligned */
041:         __u64 used_user_addr;
042:         /* Available structure address. Must be 16 bit aligned */
043:         __u64 avail_user_addr;
044:         /* Logging support. */
045:         /* Log writes to used structure, at offset calculated from specified
046:          * address. Address must be 32 bit aligned. */
047:         __u64 log_guest_addr;
048: };
049: 
050: struct vhost_memory_region {
051:         __u64 guest_phys_addr;
052:         __u64 memory_size; /* bytes */
053:         __u64 userspace_addr;
054:         __u64 flags_padding; /* No flags are currently specified. */
055: };
056: 
057: /* All region addresses and sizes must be 4K aligned. */
058: #define VHOST_PAGE_SIZE 0x1000
059: 
060: struct vhost_memory {
061:         __u32 nregions;
062:         __u32 padding;
063:         struct vhost_memory_region regions[0];
064: };
065: 
066: /* ioctls */
067: 
068: #define VHOST_VIRTIO 0xAF
069: 
070: /* Features bitmask for forward compatibility.  Transport bits are used for
071:  * vhost specific features. */
072: #define VHOST_GET_FEATURES      _IOR(VHOST_VIRTIO, 0x00, __u64)
073: #define VHOST_SET_FEATURES      _IOW(VHOST_VIRTIO, 0x00, __u64)
074: 
075: /* Set current process as the (exclusive) owner of this file descriptor.  This
076:  * must be called before any other vhost command.  Further calls to
077:  * VHOST_OWNER_SET fail until VHOST_OWNER_RESET is called. */
078: #define VHOST_SET_OWNER _IO(VHOST_VIRTIO, 0x01)
079: /* Give up ownership, and reset the device to default values.
080:  * Allows subsequent call to VHOST_OWNER_SET to succeed. */
081: #define VHOST_RESET_OWNER _IO(VHOST_VIRTIO, 0x02)
082: 
083: /* Set up/modify memory layout */
084: #define VHOST_SET_MEM_TABLE     _IOW(VHOST_VIRTIO, 0x03, struct vhost_memory)
085: 
086: /* Write logging setup. */
087: /* Memory writes can optionally be logged by setting bit at an offset
088:  * (calculated from the physical address) from specified log base.
089:  * The bit is set using an atomic 32 bit operation. */
090: /* Set base address for logging. */
091: #define VHOST_SET_LOG_BASE _IOW(VHOST_VIRTIO, 0x04, __u64)
092: /* Specify an eventfd file descriptor to signal on log write. */
093: #define VHOST_SET_LOG_FD _IOW(VHOST_VIRTIO, 0x07, int)
094: 
095: /* Ring setup. */
096: /* Set number of descriptors in ring. This parameter can not
097:  * be modified while ring is running (bound to a device). */
098: #define VHOST_SET_VRING_NUM _IOW(VHOST_VIRTIO, 0x10, struct vhost_vring_state)
099: /* Set addresses for the ring. */
100: #define VHOST_SET_VRING_ADDR _IOW(VHOST_VIRTIO, 0x11, struct vhost_vring_addr)
101: /* Base value where queue looks for available descriptors */
102: #define VHOST_SET_VRING_BASE _IOW(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
103: /* Get accessor: reads index, writes value in num */
104: #define VHOST_GET_VRING_BASE _IOWR(VHOST_VIRTIO, 0x12, struct vhost_vring_state)
105: 
106: /* The following ioctls use eventfd file descriptors to signal and poll
107:  * for events. */
108: 
109: /* Set eventfd to poll for added buffers */
110: #define VHOST_SET_VRING_KICK _IOW(VHOST_VIRTIO, 0x20, struct vhost_vring_file)
111: /* Set eventfd to signal when buffers have beed used */
112: #define VHOST_SET_VRING_CALL _IOW(VHOST_VIRTIO, 0x21, struct vhost_vring_file)
113: /* Set eventfd to signal an error */
114: #define VHOST_SET_VRING_ERR _IOW(VHOST_VIRTIO, 0x22, struct vhost_vring_file)
115: 
116: /* VHOST_NET specific defines */
117: 
118: /* Attach virtio net ring to a raw socket, or tap device.
119:  * The socket must be already bound to an ethernet device, this device will be
120:  * used for transmit.  Pass fd -1 to unbind from the socket and the transmit
121:  * device.  This can be used to stop the ring (e.g. for migration). */
122: #define VHOST_NET_SET_BACKEND _IOW(VHOST_VIRTIO, 0x30, struct vhost_vring_file)
123: 
124: /* Feature bits */
125: /* Log all write descriptors. Can be changed while device is active. */
126: #define VHOST_F_LOG_ALL 26
127: /* vhost-net should add virtio_net_hdr for RX, and strip for TX packets. */
128: #define VHOST_NET_F_VIRTIO_NET_HDR 27
129: 
130: #endif
131: 

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